Title

Author

Publication Date

12-2006

Type of Culminating Activity

Thesis

Degree Title

Master of Science in Biology

Department

Biology

Major Advisor

James C. Munger

Abstract

I studied pygmy rabbit (Brachylagus idahoensis)movements and home ranges during their breeding season in 2004 and 2005in southwestern Idaho. Pygmy rabbits were trapped, radio-collared, and tracked daily to determine average, average minimum and average maximum distances moved between telemetry points. Three home range values were also estimated; 95% Minimum Convex Polygon (MCP), 95% Fixed Kernel (FK), and 50%FK home ranges. Estimates for movements and home ranges were tested between sexes and between years. Males traveled significantly longer distances between telemetry points (average distance: males = 220 m, females = 64 m; and average maximum distance: males = 736 m, females = 321 m) and had significantly larger home ranges than females (MCP: males = 24.9 ha, females = 1.8 ha; 95%FK: males = 4.5ha, females = 1.6 ha; and 50% FK: males = 0.8 ha, females = 0.4 ha). Males also had significantly more core areas than females. Overlap of core areas was greater between sexes (male and females) as opposed to within sexes. Tests for differences between years in movements and home ranges identified only one significant difference; the average 95%FK values for females were significantly smaller in 2005compared to 2004. While the major cause for this reduction is unknown, I did note that grass cover increased 4.5%in 2005, likely due to a 100% increase in precipitation in 2005over 2004. Results of movements and home range analysis indicate that male pygmy rabbit movements are primarily driven by the spatial layout of female pygmy rabbits. Given the ability for this sagebrush obligate to travel relatively long distances, careful consideration should be given to managing pygmy rabbit habitat so as to maintain habitat patches of adequate size and connectivity for this sensitive species.